Shear pin coupling for aligned shafts



12, 1952 M. w. GREDELL 2,585,113

SHEAR PIN COUPLING FOR ALIGNED SHAFTS Filed Feb. 12. 1946 F1974 INVENTOR.

MARCELLUS' 14 GREDELL Patented Feb. 12, 1952 ATENT OFFICE SHEAR PIN COUPLING FOR ALIGNED SHAFTS Marcellus W. Gredell, Detroit, Mich., assignor to Gredell Corporation, Detroit, Mich., a corporation of Michigan Application February 12, 1946, Serial No. 647,073

4 Claims.

This invention relates to mechanical power transmission, and has particular reference to a coupling for use on the propeller shaft of a marine engine.

An object of the invention is the provision of a propeller shaft coupling, which is provided with an in-board shear pin which will obviate the necessity of dry-docking or beaching the craft in order to replace a shear pin should the propeller hit an obstruction and damage the pin.

Another object of the invention is the provision of a device of the character indicated, which is mounted in-board for ready accessibility.

Another object of the invention is the provision of a propeller shaft coupling, which is simple in construction, economical to manufacture, and easy to install and disassemble.

The foregoing and other objects and advantages of the invention will appear as the descriptions proceed, reference being made from time to time to the accompanying drawings forming part of the within disclosure, in which drawings:

Fig. 1 is an elevational view, with parts in section, of one end of the device embodying my invention.

Fig. 2 is an elevational view of the opposite end of the device shown in Fig. 1.

Fig. 3 is a longitudinal vertical section of the device illustrated in Fig. 1, and taken substantially on the line 3-3 of Fig. 1.

Fig. 4 is a' section taken on the line 4-4 of Fig. 3.

Fig. 5 is a section taken on the line 5-5 of Fig. 4

Referring now more particularly to the drawings, it will be understood that in the embodiment herein disclosed (Fig. 3), the device consists of collars I and 8 which are formed with flanges 8 and Ill, which are adapted to be secured together by means of machine screws I I, which ex-, tend through straight bores formed in the flange 9 and engage threaded bores in the flange I9, so that the flange Ill may be removed quickly by simply retracting the machine screws I I from the threaded areas.

The collar I is slotted as at 52 to accommodate a key I3 which engages a key slot formed in the end of the propeller shaft I4.

The collar 8 is adapted to accommodate the end of a drive shaft I5. A radial slot I6 is machined in the collar -8 and is adapted to accommodate the shear pin II, which extends through a slot I 8 formed in the end of the shaft I5.

In the event that the propeller strikes an obstacle, causing the shaft I4 to bind, the pin I1 is sheared from the shaft I5, permitting the shaft I5 to continue to rotate independent of the collar 8. Inasmuch as this installation is inboard, it is a simple matter to replace the shear pin II by retracting the machine screws II until the flange III is free and can be slid on the shaft I5.

Having described my invention, what I claim and desire to secure by Letters Patent is:

1. In a device of the character described, a pair of collars having matched rigid flanges adapted to be secured to one another by machine screws, a shaft extending into each of said collars, one of said shafts being keyed to one collar, the other said shaft being secured to the other collar by means of a shear pin having a length greater than the diameter of said shafts and positioned in a keyway formed along a diameter of said last named shaft.

2. In a device of the character described, the combination of a collar having a rigid flange, an axial bore in said collar, a-shaft extending into said bore, longitudinal slots in said shaft and said bore, a key in said slots, at second collar in abutting relation to said first collar and having a rigid flange, said second collar having a bore, a shaft in said bore, radial slots in said collar a keyway formed along a diameter of said lastnamed shaft, a shear pin in said last-named slots and keyway said shear pin having a length greater than the diameter of said shafts, and means to secure said flanges together for unitary rotation.

3. In a device of the character described, the combination of a drive shaft and a propeller shaft, a collar keyed for fixed rotation with said propeller shaft, said collar having a rigid peripheral flange having bores therein, a second collar having a rigid flange adapted to be secured to said first flange, said drive shaft being secured to said second collar by means of a shearable pin of greater length than the diameter of said drive shaft, said shearable pin being positioned in a keyway, disposed along a diameter 01' said drive shaft.

3 4 4. In a device of the character described, the REFERENCES CITED combination of a pair of aligned shafts, a longi- The following references are of record in the tudinal keyway in one of said shafts, a rigid flanged collar on said shaft, a keyway in said file of thls patent collar in alignment with said first named keyway 5 UNITED STATES PATENTS a key in said keyways, a keyway disposed along a b r N me Dat diameter of the second shaft, a rigid flan ed coll r 349,365 Roots Sept. 21, 1886 on said second shaft abutting said other collar 939,744 Richardson No 9, 1909 and having a radial slot in alignment with the 1,685,098 Sklovsky Sept. 25, 1928 keyway in said second shaft a pin in said slot 10 1,805,879 McKenny May 19, 1931 and said last-named keyway and means for 88- 1,941,061 Thiry Dec. 28, 1933 curing together the rigid flanges of said coll r 2,050,630 Reid Aug. 11, 1936 MARCEILUS W; GREDEIL. 

